JP4702631B2 - Fuel pump - Google Patents

Description

  The present invention relates to a fuel pump.

  Conventionally, a fuel pump in which a pump part and a motor part are housed inside a case member is known (see Patent Document 1). Such a fuel pump sucks fuel from a fuel suction part provided in the pump part. The sucked fuel is pressurized by the pump unit, and then discharged to the outside from the fuel discharge part of the cover part provided at the end opposite to the pump part via the outer peripheral side of the motor part. . The pump unit is supplied with electric power from an external power source via a terminal provided on the cover unit side. The electric power supplied to the terminal is supplied to the motor unit via the brush and the commutator. Such a conventional fuel pump feeds fuel with low conductivity, such as gasoline. Therefore, the terminals on the positive electrode side and the negative electrode side are insulated by air or fuel. Further, in the conventional fuel pump, a hole is provided in a subassembly having a terminal. Functional parts such as brushes and elastic members provided on the pump part side of the subassembly are adjusted to a predetermined posture or determined by inserting a jig or the like from a hole provided in the subassembly. .

  By the way, in recent years, from the viewpoint of environmental protection, the use of fuels containing biological alcohol such as ethanol has been expanded. However, the fuel containing alcohol has higher conductivity than the conventional fuel such as gasoline. Therefore, when a voltage is applied between the positive electrode side and the negative electrode side, current easily leaks between the positive electrode side terminal and the negative electrode side terminal using alcohol-containing fuel as a medium. In particular, when a hole is provided in the subassembly, a current path is formed through the hole. As a result, the terminal may be electrochemically corroded, possibly resulting in damage to the terminal and poor conduction. It is also conceivable to reduce current leakage by increasing the distance between the positive terminal and the negative terminal. However, when securing the distance between the terminals, there is a problem that the size of the physique increases.

Japanese Utility Model Publication No. 7-14158

  Accordingly, an object of the present invention is to provide a fuel pump in which the posture and position of functional parts are adjusted without causing an increase in the size of the physique, and the electrochemical corrosion of the terminal is reduced with a simple structure.

In the first aspect of the present invention, the hole provided in the terminal subassembly is closed by the blocking portion. By closing the hole with the blocking portion, the inflow of fuel containing alcohol into the hole is reduced. As a result, current leakage between the positive terminal and the negative terminal via the fuel flowing into the hole is reduced. Further, even if the hole is not completely blocked by the blocking portion, the area of the flow path through which the fuel containing alcohol flows is reduced. Therefore, even if a fuel containing alcohol slightly enters the hole, the electrical resistance increases and the current flow is limited. Furthermore, it is not necessary to secure a distance between the positive electrode side terminal and the negative electrode side terminal by closing the hole with the blocking portion. Therefore, even when a fuel containing alcohol is used, the electrochemical corrosion of the terminal can be reduced with a simple configuration without causing an increase in size.
In the first aspect of the present invention, for example, a jig can be inserted through the hole of the terminal subassembly. Thereby, for example, the posture and position of a functional component such as a brush or an elastic member can be accurately adjusted.
Furthermore, in the invention according to claim 1, the closing portion is integrally formed with the cover portion and the resin. Accordingly, the hole portion of the terminal subassembly is closed by the closing portion with a simple configuration and without increasing the number of parts. Therefore, current leakage between terminals can be reduced, and electrochemical corrosion of the terminals can be reduced.

  In the invention according to claim 2, a jig for determining the position of the motor portion is inserted into the hole portion. The motor unit has components that are magnetized, such as permanent magnets. Therefore, when the motor unit is assembled inside the case member, the shaft of the motor unit is likely to be displaced due to the magnetic force. Therefore, a jig is inserted through the hole of the terminal subassembly to determine the position of the shaft of the motor unit. Therefore, the attitude and position of the motor unit can be accurately adjusted, and the motor unit can be assembled precisely.

  In the invention according to claim 3, a jig for determining the position of the elastic member is inserted into the hole. For example, an elastic member such as a spring is likely to buckle or tilt when a force is applied. Therefore, when assembling the elastic member, a jig is inserted through the hole of the terminal subassembly to adjust the posture of the elastic member. Therefore, the elastic member can be assembled precisely, and the pressing force of the elastic member can be set precisely.

In the invention according to claim 4, since the closing portion is integrally formed with the cover portion and the resin, the same effect as the invention according to claim 1 can be achieved .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
A fuel pump according to an embodiment of the present invention is shown in FIG. The fuel pump 10 is an in-tank pump that is mounted inside a fuel tank such as a vehicle. The fuel pump 10 supplies the fuel inside the fuel tank to the engine. The fuel pump 10 includes a pump unit 20 that pressurizes the sucked fuel and a motor unit 30 that drives the pump unit 20. The motor unit 30 is a DC motor with a brush. The fuel pump 10 includes a substantially cylindrical housing 11. A plurality of permanent magnets 12 are annularly provided on the inner wall of the housing 11 in the circumferential direction. On the inner peripheral side of the permanent magnet 12, a rotor 31 of the motor unit 30 is disposed concentrically with the annular permanent magnet 12.

  The pump unit 20 includes a casing body 21, a casing cover 22, an impeller 23 that is a rotating member, and the like. The casing body 21 and the casing cover 22 form a substantially C-shaped pump flow path 24. An impeller 23 is rotatably accommodated between the casing body 21 and the casing cover 22. The casing body 21 and the casing cover 22 are formed by, for example, aluminum die casting. The casing body 21 is fixed to one end side in the axial direction of the housing 11 by press fitting. A bearing 25 is provided at the center of the casing body 21. The casing cover 22 is fixed to one end of the housing 11 by caulking or the like while being covered with the casing main body 21. A thrust bearing 26 is provided at the center of the casing cover 22. One end of the shaft 32 of the rotor 31 is rotatably supported by the bearing 25 in the radial direction, and an axial load is supported by the thrust bearing 26. The housing 11, the casing main body 21, and the casing cover 22 constitute a case member in the claims.

  The casing cover 22 has a fuel suction part 27. When the impeller 23 having a blade groove at the peripheral edge rotates in the pump passage 24, the fuel inside the fuel tank (not shown) is sucked into the pump passage 24 from the fuel suction portion 27. The fuel sucked into the pump passage 24 is pressurized by the rotation of the impeller 23 and is discharged to the pump chamber 13 that forms the fuel passage.

  On the other end of the housing 11, that is, on the opposite side of the casing body 21 and the casing cover 22, an end cover 40, a terminal subassembly 50, and a bearing holder 60 are provided. The terminal subassembly 50 and the bearing holder 60 are sandwiched between the end cover 40 and the housing 11. The end cover 40 is fixed to the housing 11 by caulking. The bearing holder 60 has a connection passage 61 that connects the pump chamber 13 and the fuel passage 41 of the end cover 40. As shown in FIGS. 3 and 4, the bearing holder 60 forms an accommodation chamber 62 that accommodates the brush 70 so as to be capable of reciprocating in the axial direction. The bearing holder 60 accommodates a brush 70 and a spring 71 as an elastic member in the accommodation chamber 62. The brush 70 is pressed against the rotor 31 by a spring 71. The brush 70 has a pigtail 72. The pigtail 72 is formed of a conductive wire. As a result, power is supplied to the brush 70 via the pigtail 72.

  The end cover 40 has a fuel discharge part 42 and a connector 43 on the outer peripheral side of the shaft 32 as shown in FIG. The fuel discharge part 42 has a fuel passage 41 and a pressure regulating valve 44. The fuel passage 41 is opened and closed by a pressure regulating valve 44. When the fuel pressure inside the fuel pump 10 exceeds a predetermined value, the pressure regulating valve 44 opens the fuel passage 41. The connector 43 is provided with a terminal 51. The terminal 51 is composed of a positive terminal and a negative terminal. The terminal 51 constitutes a terminal subassembly 50. As shown in FIGS. 1 and 4, the terminal subassembly 50 includes a terminal 51 and a resin body 52. The terminal 51 is provided so as to protrude from the body 52. Further, as shown in FIG. 4, a conductive member 53 protrudes from the body 52. One end of the conductive member 53 is electrically connected to the terminal 51. The conductive member 53 is connected to the pigtail 72 of the brush 70 at the end opposite to the terminal 51. As a result, the power supplied from the power source to the terminal 51 is supplied to the brush 70 via the conductive member 53 and the pigtail 72.

  The bearing holder 60 accommodates the terminal subassembly 50 between the end cover 40 as shown in FIG. The bearing holder 60 is accommodated on the inner peripheral side of the housing 11 as shown in FIG. The bearing holder 60 is provided with a bearing 63 at the center. Thus, the rotor 31 is rotatably supported by the bearing 63 at the end opposite to the bearing 25.

  The rotor 31 is rotatably accommodated in the housing 11. The rotor 31 is wound with a winding that forms a coil 33 on the outer periphery of the core. A commutator 34 is provided at an end portion on the end cover 40 side in the axial direction of the rotor 31. The commutator 34 is formed in a fan-like plate shape divided in a predetermined angle range. The commutator 34 contacts the brush 70 pressed by the spring 71. As a result, electric power is supplied from the brush 70 to the coil 33 of the rotor 31 via the commutator 34.

  Electric power supplied from a power source (not shown) to the terminal 51 is supplied to the coil 33 of the rotor 31 via the conductive member 53, the pigtail 72, the brush 70 and the commutator 34. When the rotor 31 is rotated by the electric power supplied to the coil 33, the impeller 23 is rotated together with the rotor 31 and the shaft 32. Further, when the rotor 31 rotates, the commutator 34 rotates accordingly. At this time, the commutator 34 rotates while maintaining a contact state with the brush 70. When the impeller 23 rotates together with the shaft 32 of the rotor 31, fuel is sucked into the pump flow path 24 from the fuel suction portion 27. The fuel sucked into the pump passage 24 receives kinetic energy from each blade groove of the impeller 23 and is discharged from the pump passage 24 to the pump chamber 13. The fuel discharged into the pump chamber 13 is supplied to the outside of the fuel pump 10 via the periphery of the rotor 31 and the fuel passage 41. Here, the pump chamber 13 constitutes the fuel passage of the claims.

Next, the vicinity of the terminal subassembly 50 will be described in detail.
The terminal subassembly 50 has a resin body 52 as shown in FIG. As shown in FIGS. 1 and 5, the body 52 has a hole portion 54 penetrating in the axial direction at the center. As shown in FIG. 3, the hole portion 54 communicates with the through hole portion 64 of the bearing holder 60 when attached to the bearing holder 60. The through hole 64 is provided between the storage chambers 62 in the radial direction of the bearing holder 60 and penetrates the bearing holder 60 in the axial direction. As shown in FIG. 2, a bearing 63 is provided in the through hole portion 64 of the bearing holder 60, and the shaft 32 of the motor unit 30 is inserted therein.

  When the motor unit 30 is assembled to the terminal subassembly 50 and the bearing holder 60, a jig for determining the position of the motor unit 30, particularly the rotor 31, is inserted via the hole 54 and the through hole 64. The motor unit 30 has magnetized parts such as the permanent magnet 12. Therefore, when the motor unit 30 is assembled inside the housing 11, the motor unit 30 is likely to be displaced due to the magnetic force. Therefore, a jig is inserted through the hole 54 of the terminal subassembly 50 and the through hole 64 of the bearing holder 60 to determine the position of the shaft 32 of the motor unit 30. Thereby, the attitude | position and position of the motor part 30 can be adjusted correctly, and the motor part 30 can be assembled | attached precisely.

  The body 52 has a plate portion 55 on the radially outer side of the hole portion 54 as shown in FIGS. 1, 3, 4, and 5. The plate portion 55 closes the end portion of the accommodation chamber 62 formed by the bearing holder 60 on the side opposite to the motor portion 30. The plate portion 55 is formed with a hole portion 56 penetrating in the plate thickness direction, that is, the axial direction of the terminal subassembly 50. Thus, when the terminal subassembly 50 and the bearing holder 60 are assembled, the hole 56 communicates with the accommodation chamber 62. The spring 71 is accommodated in the accommodation chamber 62 as described above. The end of the spring 71 opposite to the brush 70 is in contact with the plate portion 55. The spring 71 tends to buckle or tilt when a force is applied. When the spring 71 is buckled or tilted, the force for pressing the brush 70 changes. Therefore, when the spring 71 is assembled, a jig is inserted through the hole 56 of the terminal subassembly 50 to adjust the posture of the spring 71. Therefore, the spring 71 is assembled accurately in the correct posture, and the pressing force of the spring 71 can be set precisely. Thus, in this embodiment, the spring 71 and the pump part 30 comprise the functional component of a claim.

  As described above, the body 52 of the terminal subassembly 50 is formed with the hole portion 54 and the hole portion 56 into which jigs for determining the positions and postures of the motor portion 30 and the spring 71 can be inserted. On the other hand, the fuel pump 10 passes around the terminal subassembly 50 while the fuel sucked from the fuel suction portion 27 is discharged to the fuel discharge portion 42. For this reason, in the case of a fuel containing a highly conductive substance such as alcohol, for example, current leakage may occur between the positive electrode side and the negative electrode side terminal 51 through the hole portion 54 and the hole portion 56. is there.

  Therefore, in the present embodiment, the end cover 40 is provided with the closing portion 80. The closing part 80 is provided inside the end cover 40. As shown in FIG. 1, the end cover 40 is formed in a cylindrical shape, and an end portion on the opposite side to the motor portion 30 is closed by a top portion 45. The blocking part 80 protrudes from the top part 45 to the motor part 30 side. The closing portion 80 includes a protruding portion 81 provided at the center portion of the end cover 40 and a base portion 82 provided on the outer peripheral side of the protruding portion 81. The protrusion 81 and the base 82 are integrally formed with the top 45 of the end cover 40 and resin.

  The protruding portion 81 protrudes from the center portion of the end cover 40 toward the motor portion 30 side. Thus, when the end cover 40 is assembled to the terminal subassembly 50, the protrusion 81 is inserted into the hole 54 of the body 52. Thereby, the protruding portion 81 closes the hole portion 54 of the body 52. On the other hand, the base portion 82 is provided on the outer peripheral side of the protrusion portion 81 of the end cover 40 and protrudes toward the motor portion 30 side. The base part 82 protrudes from the top part 45 of the end cover 40 to the motor part 30 side like a base. Thereby, when the end cover 40 is assembled to the terminal subassembly 50, the base portion 82 closes the end portion of the hole portion 56 of the body 52 opposite to the motor portion 30.

  In this way, by closing the hole portion 54 and the hole portion 56 of the body 52 with the protrusion 81 or the base portion 82, the path through which current leaks between the terminals 51 on the positive electrode side and the negative electrode side is blocked. In this case, by closing the hole portion 54 and the hole portion 56 of the body 52 with the protrusion portion 81 or the base portion 82, even if the hole portion 54 and the protrusion portion 81 or the hole portion 56 and the base portion 82 are not in close contact with each other, The area of the path through which the current flows is reduced. As a result, the resistance of the current path formed between the hole 54 and the protrusion 81 or the hole 56 and the base 82 is increased, and current leakage between the positive and negative terminals 51 is reduced. Is done.

  As described above, in one embodiment of the present invention, the hole portion 54 and the hole portion 56 of the body 52 are closed by the protruding portion 81 or the base portion 82 provided in the end cover 40. For this reason, the current path is interrupted or the area of the current path is reduced between the terminals 51 on the positive electrode side and the negative electrode side. As a result, even when a fuel containing highly conductive alcohol is used, leakage of current between the terminals 51 is reduced when a voltage is applied between the terminals 51 on the positive electrode side and the negative electrode side. Therefore, the electrochemical corrosion of the metal terminal 51 is reduced, and damage to the terminal 51 can be reduced. Moreover, it is not necessary to secure a large distance between the terminals 51 by closing the hole portion 54 and the hole portion 56 with the protruding portion 81 or the base portion 82. Therefore, the enlargement of the physique can be avoided. Further, the protrusion 81 and the base 82 provided on the end cover 40 are formed integrally with the top 45 of the end cover 40. Therefore, the number of parts is not increased and the structure is not complicated.

  Further, in one embodiment of the present invention, the terminal subassembly 50 is provided with a hole 54 and a hole 56. Thereby, the position and attitude | position of the motor part 30 and the spring 71 are adjusted with the jig | tool inserted in the hole part 54 or the hole part 56. FIG. Therefore, the motor unit 30, the brush 70, and the spring 71 can be assembled precisely.

In the embodiment of the present invention described above, the spring 71 and the pump unit 30 have been described as examples of functional components. However, the functional component is not limited to the spring 71 and the pump unit 30, and may be another component such as a bearing that supports the pump unit 30.
As described above, the present invention described above is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the scope of the invention.

1 is an enlarged schematic cross-sectional view of an end cover and a terminal subassembly of a fuel pump according to an embodiment of the present invention. 1 is a cross-sectional view schematically showing a fuel pump according to an embodiment of the present invention. (A) is an arrow view seen from arrow III direction of FIG. 2, (B) is sectional drawing in the BB line of (A). FIG. 4 is a schematic exploded view showing an assembled state of an end cover, a terminal subassembly, a brush, and a bearing holder of a fuel pump according to an embodiment of the present invention, as viewed from the direction of arrow IV in FIG. (B) is a view seen from the direction of arrow B in (A). The arrow view which looked at the terminal subassembly of the fuel pump by one Embodiment of this invention from the arrow V direction of FIG. 1 (B).

Explanation of symbols

  10: fuel pump, 11: housing (case member), 13: pump chamber (fuel passage), 20: pump section, 21: casing body (case member), 22: casing cover (case member), 27: fuel suction section , 30: motor part (functional part), 34: commutator, 40: end cover (cover part), 42: fuel discharge part, 50: terminal subassembly, 51: terminal, 54: hole part, 56: hole part, 70: Brush, 71: Spring (elastic member, functional part), 80: Closure part, 81: Projection part, 82: Base part

Claims (4)

A case member having a fuel suction portion and forming a fuel passage therein;
A cover portion provided at an end of the case member opposite to the fuel suction portion and having a fuel discharge portion for discharging fuel;
A pump part provided at an end of the case member opposite to the cover part, for pumping fuel sucked from the fuel suction part to the fuel discharge part;
A motor unit that is provided inside the case member, has a commutator at an end opposite to the pump unit, and drives the pump unit;
A plurality of brushes that contact the commutator and supply power to the motor unit;
An elastic member that presses the brush toward the commutator;
A terminal subassembly having a terminal housed in the cover portion and connected to a power source for supplying power to the motor portion, and a hole portion for assisting in assembling a functional component located on the motor portion side of the terminal When,
A blocking portion for closing the hole;
Equipped with a,
The closing section, a fuel pump that is integrally formed with the cover portion and resin. A case member having a fuel suction portion and forming a fuel passage therein;
A cover portion provided at an end of the case member opposite to the fuel suction portion and having a fuel discharge portion for discharging fuel;
A pump part provided at an end of the case member opposite to the cover part, for pumping fuel sucked from the fuel suction part to the fuel discharge part;
A motor unit that is provided inside the case member, has a commutator at an end opposite to the pump unit, and drives the pump unit;
A plurality of brushes that contact the commutator and supply power to the motor unit;
An elastic member that presses the brush toward the commutator;
A terminal subassembly having a terminal housed in the cover portion and connected to a power source for supplying power to the motor portion, and a hole portion for assisting in assembling a functional component located on the motor portion side of the terminal When,
A blocking portion for closing the hole;
With
The hole portion is capable of inserting a jig for determining the position of the motor portion between the plurality of brushes,
The closing portion projects from said cover portion to said terminal subassembly side, fuel pump Ru projections der to be inserted into the hole. A case member having a fuel suction portion and forming a fuel passage therein;
A cover portion provided at an end of the case member opposite to the fuel suction portion and having a fuel discharge portion for discharging fuel;
A pump part provided at an end of the case member opposite to the cover part, for pumping fuel sucked from the fuel suction part to the fuel discharge part;
A motor unit that is provided inside the case member, has a commutator at an end opposite to the pump unit, and drives the pump unit;
A plurality of brushes that contact the commutator and supply power to the motor unit;
An elastic member that presses the brush toward the commutator;
A terminal subassembly having a terminal housed in the cover portion and connected to a power source for supplying power to the motor portion, and a hole portion for assisting in assembling a functional component located on the motor portion side of the terminal When,
A blocking portion for closing the hole;
With
The hole can be inserted with a jig for positioning the elastic member,
The closing portion projects from said cover portion to said terminal subassembly side, the cover portion of the block the end base portion der Ru fuel pump of the hole. The fuel pump according to claim 2 or 3, wherein the closing portion is integrally formed with the cover portion and resin.

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